Does growth hormone (GH) enhance growth in GH-deficient children with myelomeningocele?

Short stature and the effect of human growth hormone: Guidelines for the care of people with spina bifida

It is estimated that a significant percentage of individuals with spina bifida (SB) are shorter than their age-matched typical peers. Parents of children with spina bifida may ask if human growth hormone is appropriate for their child. This article discusses short stature and the use of human growth hormone among children with SB. This guideline was developed for SB Healthcare Guidelines from the 2018 Spina Bifida Association's Fourth Edition of the Guidelines for the Care of People with Spina Bifida.

Kaolin-induced hydrocephalus causes acetylcholinesterase activity dysfunction following hypothalamic damage in infant rats

In hydrocephalus, the progressive accumulation of cerebrospinal fluid (CSF) causes dilatation of the lateral ventricles affecting the third ventricle and diencephalic structures such as the hypothalamus. These structures play a key role in the regulation of several neurovegetative functions by the production of the hormones. Since endocrine disturbances are commonly observed in hydrocephalic children, we investigated the impact of progressive ventricular dilation on the hypothalamus of infant rats submitted to kaolin-induced hydrocephalus. Seven-day-old infant rats were submitted to hydrocephalus induction by kaolin 20% injection method. After 14 days, the animals were decapitated and brain was collected to analyze mitochondrial function, neuronal activity by acetylcholinesterase (AChE) enzyme, oxidative damage, glial activation, and, neurotransmission-related proteins and anti-apoptotic processes in the hypothalamus. The hydrocephalic animals showed reduction in respiratory rates in the States of phosphorylation (P < 0.01) and non-phosphorylation (P < 0.05); increase in AChE activity in both the cytosol (P < 0.05) and the membrane (P < 0.01); decrease in synaptophysin (P < 0.05) and Bcl-2 (P < 0.05) contents and; increase in protein carbonyl (P < 0.01), GFAP (P < 0.01) and Iba-1 (P < 0.05) levels. The results demonstrate that ventricular dilation causes hypothalamic damage characterized by cholinergic dysfunction and suggests further investigation of the synthesis and secretion of hormones to generate new approaches and to assist in the treatment of hydrocephalic patients with hormonal alterations.

Update on bone fragility in spina bifida

BACKGROUND CONTEXT

Patients with spina bifida (SB) are at risk for pathological fractures and low bone mineral density (BMD).

PURPOSE AND METHODS

This article reviews the literature and provides a comprehensive overview of how the characteristics of SB and its associated comorbidities intersect with bone fragility to identify possible pathophysiological mechanisms of fractures and low BMD.

RESULTS

Bone fragility occurs early in the life of patients with SB as a result of a disturbance that determines changes in bone shape, quantity, and quality, as poor mineralization reduces bone stiffness. Bone fragility in SB occurs due to local and systemic factors and may be considered a state of impaired bone quality of multifactorial aetiology, with complex interacting influences of neurological, metabolic, and endocrinological origins and the presence of smaller bones. Bone fragility should be evaluated globally according to skeletal age and Tanner staging. The phases of the evolution of Charcot joints seem to intercept the evolution of epiphyseal fractures. Charcot arthropathy in SB may be initiated by the occurrence of repetitive trauma and fractures in epiphyseal and subepiphyseal regions, where there is a deficit of bone mineralization and greater bone mass deficits.

CONCLUSION

Bone fragility in MMC potentially has a multifactorial neuro-endocrinological-metabolic-renal dimension, with smaller bones, lower bone mass, and mineralization deficits affecting bone strength.

Neuropathology and structural changes in hydrocephalus

In the context of spina bifida, hydrocephalus is usually caused by crowding of the posterior fossa with obstruction to cerebrospinal fluid flow from the forth ventricle, and less often by malformation of the cerebral aqueduct. Enlargement of the cerebral ventricles causes gradual destruction of periventricular white matter axons. Motor, sensory, visual, and memory systems may be disturbed through involvement of the long projection axons, periventricular structures including the corpus callosum, and the fimbria-fornix pathway. Secondary changes occur in neuronal cell bodies and synapses, but there is minimal death of neurons. The clinical syndrome of hydrocephalic brain dysfunction is thus due to subcortical disconnection. Some of the brain dysfunction is reversible by shunting, probably through restoration of cerebral blood flow and normalization of the extracellular environment. However, destroyed axons cannot be restored.

Growth in pre-pubertal children with myelomeningocele (MMC) on growth hormone (GH): The KIGS experience

PURPOSE

To analyse the auxological data of children with myelomeningocele (MMC) on growth hormone (GH) therapy whose growth data was documented within KIGS (Pfizer International Growth Database). Longitudinal growth data of a sub-group of pre-pubertal children were studied after a treatment period of 3 years.

PATIENTS AND METHODS

Eighty patients (38 m, 42 f) with MMC with a median chronological age (CA) of 11.6 years (at latest visit) on GH were registered in the KIGS database. In 52 patients, GH deficiency was documented. GH therapy started with a median dose of 0.23 mg kg(-1) per week. The 3-year longitudinal growth was analysed in 21 patients (13 m, 8 f; median CA 9.2 years, latest visit), all of whom were pre-pubertal at start and during GH therapy.

RESULTS

GH therapy started at 7.5 years with a dose of 0.23 mg kg(-1) per week. Birth length SDS (-0.51) and mid-parental height SDS (+0.07) were in the normal range. BMI SDS at start was +0.24, at latest visit -0.03. After a median treatment duration of 3.0 years (latest visit), height SDS improved from -2.97 (start of GH) to -2.01. The sub-group of pre-pubertal MMC patients started GH therapy (dose 0.22 mg kg(-1) per week) at 6.2 years. Growth velocity (GV) SDS increased significantly (at start: -1.77; 1 year: +2.60, 2 years: +2.25, 3 years: +1.24), thus height SDS improved from -3.25 at start to -1.87 at 36 months. BMI SDS was in the normal range and remained unchanged during GH therapy. No major side effects of GH were recorded.

CONCLUSION

GH had positive effects on height SDS in MMC patients. The analysis of the longitudinal growth data of pre-pubertal MMC patients showed a significant increase in GV SDS and improvement of height SDS.

Floating-Harbor syndrome complicated by tethered cord: A new association and potential contribution from growth hormone therapy

Floating-Harbor syndrome is a rare syndrome with short stature, severely delayed bone age, typical facies and delay in expressive speech. Structural malformations are uncommon, and tethered cord or other forms of spinal dysraphism have not previously been reported. We report on a case of Floating-Harbor syndrome, complicated by tethered cord and discuss the possibility that growth hormone therapy may contribute to the development of symptoms of this malformation.

Evaluation of femur length during the second and third trimesters in fetuses with myelomeningocele

OBJECTIVES

To determine if the femur length of fetuses with myelomeningocele is shorter in the second and third trimesters compared with that of normal fetuses.

METHODS

We retrospectively collected measurements of femur length, head circumference, biparietal diameter and abdominal circumference from detailed obstetric ultrasound studies performed during the second and third trimesters in 31 fetuses with myelomeningocele and 43 fetuses with no detectable anomaly. The gestational age predicted by each parameter (based on Hadlock's tables) was compared with the true gestational age (based on last menstrual period), using the ANCOVA test to determine if there was a statistically significant difference between the two groups of fetuses.

RESULTS

There was no significant difference in femur length (P = 0.60) or in abdominal circumference (P = 0.85) between fetuses with myelomeningocele and normal fetuses. Fetuses with myelomeningocele did have a significantly lower biparietal diameter and head circumference (P < or = 0.001).

CONCLUSIONS

Myelomeningocele is not associated with reduced femur length in the second and third trimesters, suggesting that the known postnatal lower extremity foreshortening in patients with myelomeningocele develops late in gestation or after birth.